Interrupter for rotary printing machines



1964 F. s. THOMPSON 3,163,110

INTERRUPTER FOR ROTARY PRINTING MACHINES Filed Sept. 20, 1962 3 Sheets-Sheet l INVENTOR:

Dec. 29, 1964 F. s. THOMPSON 3,163,110

INTERRUPTER FOR RQTARY PRINTING MACHINES Filed Sept. 20, 1962 3 Sheets-Sheet 2 INVENTOR}.

Dec. 29, 1964 F. s. THOMPSON 3,163,110

INTERRUPTER FOR ROTARY PRINTING MACHINES Filed Sept. 20, 1962 3 Sheets-Sheet 3 INVENTOR:

United States Patent Ofilice 3,163 ,1 l Patented Dec. 29, 1964 3,163,110 INTERRUPTER FOR ROTARY PRINTING MACHINES Frank Sydney Thompson, Cheadle Hnlme, England,

assignor to T. C. Thompson & Son Limited, Manchester, England, a corporation of Great Britain Filed Sept. 20, 1962, Ser. No. 225,106 Claims priority, application Great Britain Sept. 21, 1961 1 Claim. (Cl. 101-247) This invention relates to rotary printing machines of the type in which a plate cylinder is mounted to swing into and out .of engagement with a stationary impression cylinder which feeds sheets for printing between the nip of the two cylinders.

It has been proposed in a machine having a plate cylinder carrying soft letterpress moulded in relief on a rubher or other resilient sheet to stand proud of the surface to mount the plate cylinder on a frame pivoted about the axis of an inking drum to be capable of being moved into and out of contact with the impression cylinder Whilst remaining in contact with the inking drum.

Such an arrangement cannot be employed with thin hard letterpress printing plates curved around and mounted on the plate cylinder and having the raised letterpress etched out of the printing plate due to the more complicated inking mechanism requiring soft inking rollers interposed between the drum and the type and the object of the present invention is to provide a swinging unit for use with such machines.

According to the invention the plate cylinder and inking rollers are mounted in a frame pivoted on the axis of an inking drum, means being provided to swing the frame into and out of engagement with a stationary impression cylinder without disturbing the setting of the plate cylinder and rollers.

The invention will be described with reference to the accompanying drawings:

FIG. 1 is a diagrammatic side elevation of the ink supply rollers to the plate cylinder C mounted on the frame B and showing the plate in contact with the impression cylinder C, the mountings for the inking rollers b, b and the cam D being omitted for clearness.

FIG. 2 is an enlarged elevation showing the inking rollers b, Z1 and cam D mounted on the frame B.

FIG. 3 is a vertical section showing the mounting of the frame and plate cylinder and inking rollers.

The printing machine A is provided with an ink duct a and feed rollers a for supplying ink to an ink drum A in which ink is taken up by a roller 41 from the duct :1 and transferred to a vibrating roller (1 which intermittently delivers the ink to the first feed roller a and through the train of rollers a The cylinders and feed rollers may also be driven in known manner.

The ink drum A is mounted on the shaft a to rotate in the main frame A of the machine and an impression cylinder C and sheet feeding mechanism 0 therefor are also mounted in the main frame A.

The impression cylinder C is mounted to rotate about a fixed axis in the machine frame so that the relationship between it and the feed and delivery mechanism need not be disturbed.

A plate cylinder C carries a thin plate (of the order of 0.025 inch thick with the letterpress or the like etched or otherwise formed thereon about 0.010 inch deep) curved around the mriphery of the cylinder and secured to the cylinder in known manner. The plate cylinder C is mounted on a concentric shaft 0 rotatably mounted in a frame B pivoted on the shaft a on which the ink drum A is mounted. The impression cylinder C is connected to the plate cylinder C by an arm C at each end of the cylinder, each arm engaging an eccentric portion C of the shaft 0 upon which the plate cylinder C is mounted, rotation of the shaft 0 bringing the plate cylinder C into or out of contact with the impression cylinder C as shown in chain dotted lines in FIG. 1.

The frame B may be rocked about the shaft a from the position shown in FIG. 1 to the chain dotted position to bring the plate cylinder C into 01' out of engagement with the impression cylinder C by a lever D mounted on a spindle d carried in the machine frame A, through an arm d also mounted on the spindle d and provided with a roller d engaging a slot in aforked bracket b mounted on the shaft c about which the plate cylinder C rotates. The bearings for the shaft c in the arms C are eccentric with respect to the plate cylinder C whereby movement of the lever D from the position shown in FIG. 1 in the direction of the arrows brings the plate cylinder C out of engagement with the impression cylinder C by rotating the eccentric shaft 0. The lever D when in the position shown in FIG. 1 exerts pressure between the plate cylinder C and the impression cylinder C to retain the two cylinders in contact.

In order to adjust the pressure and alignment between the plate cylinder C and the impression cylinder C this latter is mounted on a shaft 0 and provided with an eccentric bush c at each end. The bushes c are provided with teeth on a portion of their periphery engaged by worm wheels 0 rotation which displaces the levers C and consequently the frame B to vary the distance between the axes of the shafts c, 0 when the cylinders are in contact and thus the pressure exerted therebetween and allow for correction of the alignment of the cylinder.

Two or more inking rollers b, I) for transferring ink from the ink drum A to the plate cylinder C are mounted on the frame B to move therewith about the shaft a and thus the plate cylinder C may be brought into or out of engagement with the impression cylinder C or adjusted for pressure without disturbing the settings of the rollers b, b

The ink rollers Z2, b may be of a circumference equal to the longest sheet to be printed, thus obviating repeats and may be mounted on the independent frame B in hearing recesses in levers 12 I2 to swing tangetically to the surface of the ink drum A When the plate cylinder C is brought out of engagement with the impression cylinder C it may be desirable to also interrupt the inking of the plate cylinder by lifting the inking rollers b, 12 out of engagement therewith or in addition to interrupt the supply of ink to the first feed roller a A three armed cam D is pivoted on the frame B having two cam surfaces d @1 to engage respectively the levers b b as the cam D is rotated from position 1 in FIG. 2 to position 2 (shown chain dotted) by a lever D to lift the arms b b to bring the inking rollers b, b out of contact with the plate cylinder C In order to interrupt the supply of ink to the vibrating roller a one end of a rod a is pivoted to the third arm of the cam D the other end being pivoted to a pivoted link a on the frame A movement of the lever D bringing the link a into engagement with a rod a depending from a cradle carrying the vibrating roller a to arrest the movement of the cradle. The initial movement of the cam D from position 1 to position 2 does not bring the link a into engagement with the rod a and the movement of the cam D from position 2 to position 3 does not affect the movement of the rollers b, b as a radial portion of the cam surfaces d c1 engages the levers b b The pressure between the inking rollers b, b and the drum A is adjusted by pivoting the levers b 17 on eccentric fulcrum pins b rotation of which by levers Z1 --=raises or lowers ithe rollers b, b M .ipressure. ,betweensthe rollers .b, 123 .andth Pl t ,QYl E Adjustment of the C is obtained through pins b engaging the inner surface of each lever b 17 The pins b are also eccentric so s-ithabrotation byleversbii .againstrthenaction ofrsprings b --causes-.thelevers b b to move transversely.

Theeccentric-fulcrum pins 72 are. locked in position against the plate B hy..-;nuts b v screwed thereon. Further-nuts [J3 screwedzontoxthe pins bi. lockithese pins to M the plate B.-.:='1he 1'evers b b may be rocked to bring the--rollers b, b clear of {both the inking drum A1, and :the-plate' cylinder (1, for removal by pins 12 ona pivoted --shaft b actuated by .a,contr.o1 farm [2? tov cause, the pins -b -t engagethe'tail ends 12 of the. levers.

:Lclazirn: 'A rotary printing machine, comprising a support, an

pivotally mounting said shafts at the other end, the rock- =able mounting ofsaid'one. end of.:said arms being ec- ,.,;uc'entric to theaxis of said impression cylinder and said plate cylinder in printing position being disposed in printir g engagement with said impression cylinder to define a nip through which pass the sheets to be printed, means for adjusting said eccentric mounting to vary the printing engagement pressure between the impression and plate cyinders, a plurality of inking rollers mounted for rotation on said frame about their axes and normally having peripheral ink transfer contact with both said inking drum I and said plate cylinder, and cooperating means on said frame andrsaid arms adjustable for swinging said frame about the axis of saidninking drum for displacing said plate cylinder out of printing engagement with said impression cylinder While maintaining said inking rollers in engagement with both said inking drum and said plate cylinder.

References Cited in the file of this patent UNITED STATES PATENTS 971,765 Nlain Oct. 4, 1910 1,301,970 Pritchard Apr. 29, 1919 1,966,311 Pearson et al July 10, 1934 2,026,434 Quick et a1. Dec. 31, 1935 2,387,750 Davidson Oct. 30, 1945 FOREIGN PATENTS 427,471 Germany July 29, 1925 

